Volkswagen Repair: Loss of Power, auto box, turbo charger

Question
Hi There,    (MK4 1999)90BHP
        I own a Golf 1.9 TDi Auto Since I got the car it seems to have less and less power. I have just spent £1200 on a recon auto box and still the problem continues. The engine seems to be running fine no smoke starts well but the power does not tranfer to the wheels. Even on the motorway if I come to a hill the car slow down the box will try to change down but to no avail then it changes back up. Its like driving well the hand brake on for the won't of a better description
Can u help me please
money is short now after the latest repair bill

Answer
In the USA the MK4 diesels have OBD2 DTC(diagnostic trouble codes). If you have this system then first download the fault codes. Otherwise, check the simplist things first and work your way up to more complicated systems. Always on a diesel you check the compression first. Compression is everything for a diesel. Then check the injection pump for pressure. Then check the fuel filter for water and contamination. Also you must check the turbo charger for sure. If the turbo charger isn't working then you will definitely experience a BIG loss of power. In fact, check the turbo charger and system first!